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INDUCTOR Filed Sept. 3. 1954 3 Sheets-Sheet 1 Ema-@L v INVENTOR, inn/c5L SIMMo/vs ,4 TTORNESJ 'L. L. SIMMONS INDUCTOR 3 Sheets -Sheet 2 FindSept. 5. 1954 w a M Q IL 4 0 owl WA M x a a,

United States Patent INDUCTOR Lance L. Simmons, Detroit, Mich.,assignor, by mesne assignments, to American Radiator & Standard SanitaryCorporation, New York, N. Y., a corporation of Delaware ApplicationSeptember 3, 1954, Serial No. 454,163

9 Claims. (Cl. 98-68) The present invention relates to an airconditioning unit, and more particularly to such a unit wherein primaryair is used to induce a flow of room air through a heat exchanger, theresultant mixture being discharged into the space being conditioned.

It is a principal object of the present invention to provide an airconditioning unit wherein primary air is used under optimum conditionsto assure a high rate of efliciency in inducing a flow of air through aheat exchanger.

It is another object of the present invention to provide an airconditioning unit which is flexible in use and readily adaptable tovarious installation and operation conditions. i

It is a further object of the present invention to provide an inductiontype air conditioning unit which is eflicient in operation andrelatively simple in design.

Other objects of this invention will appear in the following descriptionand appended claims, reference being had to the accompanying drawingsforming a part of this specification wherein like reference charactersdesignate corresponding parts in the several views.

In the drawings:

Fig. 1 is a front elevation of a six tube pass serpentine coil airconditioning unit embodying the present invention.

Fig. 2 is a view similar to Fig. l with the front plate removed.

,Fig. 3 is a sectional elevation taken along line 3-3 in the directionof the arrows, Fig. 2.

Fig. 4 is a fragmentary sectional view taken along the line 4-4 in thedirection of the arrows, Fig. 3.

Fig. 5 is a fragmentary view showing the arrangement with a four tubepass coil unit.

Fig. 6 is a fragmentary view of another embodiment showing a six tubepass coil unit utilizing a novel drain trough structure.

Fig. 7 is a view similar to Fig. 6 showing the particular drain troughstructure used with a four tube pass coil unit.

Fig. 8 is a sectional elevation of one of the coil end covers used withthe air conditioning unit of the present invention.

Before explaining the present invention in detail, it is to beunderstood that the invention is not limited in its application to thedetails of construction and arrangement of parts illustrated in theaccompanying drawings, since the invention is capable of otherembodiments and of being practiced or carried out in various ways. Also,it is to be understood that the phraseology or terminology employedherein is for the purpose of description and not of limitation.

Referring to the drawings, the air conditioning unit of the presentinvention includes a housing 10 having a primary air inlet 12 which isadapted to be affixed to a conduit connected with a source of air underpressure. The primary air inlet 12 is at one end of a wind box 14, and asimilar opening and collar is provided at 16 at the opposite end of thewind box. Either of these openings may be used as the primary air inlet,and the other opening is provided ice with a cap containing a wind boxpressure tap. This permits the primary air line to be brought in fromeither side of the unit. The primary air supply is controlled by anon-resonant butterfly valve (not shown) located on the air inlet sideof the unit. Thus, the primary air nozzle pressure may be adjusted tothe desired value by moving the butterfly valve to the proper position.

The primary air is moved from the air inlet 12 into the wind box 14 andthrough a slotted internal distributor baflle 18 into the internal mainair feed duct 20. It has been found that two slots in the distributorbaflle 18 provided respectively at points one-quarter and three quartersthe length of the wind box 14 produce good distribution of pressure sothat the jet of air issuing from the longitudinally elongated primaryair outlet opening 22 will have substantially uniform pressuresthroughout its length. As shown in Fig. 3 outlet opening 22 is locatedat the juncture between wind box wall section 19 and planar extension 17of backwall 24. Although extension 17 and wall section 19 do not extendin the same plane they may be considered to broadly form one wall of box14.

Internal surfaces 21 of the wind box 14 and primary air passage 20preferably are treated with material having thermal insulation and soundattenuation properties to minimize heat loss from the apparatus and toreduce noise of operation.

Referring to Fig. 4 it will be seen that bosses 26 are provided forcontrolling the width of opening 22 with accuracy. The effective area ofopening 22 and the velocity of the primary air with respect to the areaof heat exchanger 32 may be controlled by a plastic insert 28 havingspaced longitudinally elongated openings 30. It will be understood thatthe term longitudinal as used herein refers to directions at rightangles to the plane of Fig. 3 in the drawings (i. e. parallel to thelongest dimension of the air conditioner unit).

It will be noted that the backwall 24 includes a flat wall portion 23extending to a point 35 to cooperate with longitudinal wall portion 50in forming a restricted throat passage 42. A heat exchanger 32 isangularly disposed in spaced relation to the backwall. The heatexchanger 32 shown in Fig. 1 has a six tube pass coil heat exchangeelement 34. Fins 36 are provided around the coil which is connected to asuitable source of coolant or heating fluid.

As previously stated, the room air is induced through the room air inlet38 and heat exchanger 32 by the jet of primary air. The general theoryof flow induction is well known. A stream of fluid issuing at highvelocity into a relatively quiet fluid body will impart a portion of itsenergy of motion to the quiet fluid body and set it into motion in thedirection of the original stream or jet. This exchange of energy takesplace at the boundary surface of the stream or jet. It has been found byexperiment that the total angle between the sides of a confinednon-inductive jet is approximately 3 5 whereas the angle between thesides of an air inducing jet issuing into free air is between 6 and 7.Any conditions which vary this angle beyond the indicated limits willlimit induction or entrainment.

The air conditioning unit of the present invention utilizes thisphenomenon in its construction. The jet of pri mary air issuing fromnozzle 22 hugs the smooth metal backwall 24 and the form of the jet isdefined by the backwall which although preferably curved at 35 as shown,can be either vertical or sloped. The heat exchanger 32 is so positionedwith respect to backwall 24 as to form the angle best suited to theexpansion of the jet through induction of room air through the heatexchanger. The inner edges 25 of the heat exchanger coils 27 extend atan angle of about three degrees with respect to wall 24 when measured indirections from the nozzle opening. It is believed that edges 25 have atendency to confine the jet from nozzle 22 so as to minimize eddy lossesbetween the primary air and secondary air. Test results indicate thatmaximum amounts of induced air are obtained when edges 25 are in theirillustrated positions with respect to back wall 24.

Positioned directly above the induction portion of the unit is the evase40 of a Venturi formed by diverging wall portions 47 and 48. ThisVenturi includes the restricted throat 42. The mixture of primary airand induced room air is passed into the throat 42 and then out theVenturi construction through the outlet 44. This increases theefiiciency of the air induction. It is known that a Venturi has minoreffect in air induction when there is no resistance to the flow of thesecondary or induced air, but a Venturi has definite advantages whenthere is resistance to secondary air flow as in the present case withthe heat exchanger.

The backwall 24 works smoothly into the Venturi construction at 35 andpermits less angularity of the heat exchanger 32.

The fore plate 46 is divided into two wall portions 48 and 50. Entry andremoval of the heat exchanger 32 with respect to the assembly isfacilitated by this construction. When the heat exchanger is in theassembled position, the fore plate 46 is joined through wall portions 48and 50 by suitable means such as the bolts 52.

A modification of the fore plate construction is shown in Fig. 5. Inthis embodiment a four tube pass coil rather than a six tube pass coilheat exchanger is used. Fore plate wall portion 50 is elongated tocompensate for the smaller height of the four tube pass coil heatexchanger.

A further modification is shown in Fig. 6 of the drawings. A six tubepass coil unit is shown. In this instance member 50b is curved over theend of heat exchanger 32b to provide a narrow drain trough 55b. Anoutlet pipe 54b is used to pass ofi collected moisture. The position ofthe air conditioner unit when used horizontally can be demonstrated byplacing Fig. 1 of the drawing on its side. Moisture which is condensedon the coils 34 will rundown the sloping heat exchanger 32 into draintrough 55]) (Fig. 6) and through outlet pipe 54b. Thus, the unit may behorizontally disposed without the necessity of using a full width drainpan.

Fig. 7 shows the construction of Fig. 6 modified for use with a fourtube pass coil heat exchanger. As in Fig. 5, the fore plate section 50cis elongated to accommodate the shorter heat exchange unit.

A coil end cover 56 is shown in Fig. 8. It consists of a housing 58 andan attaching flange 60. One of these covers is placed over the returnbends of the coils on each side of the air conditioning unit. Thesecovers drain condensate into the main drip pan such as 62 (Fig. 3).

From the foregoing, it will be seen that I have provided a simple andefiicient induction type air conditioning unit, which is extremelyversatile. The unit provides a unique, aerodynamically correctcombination of a primary air nozzle, expansion chamber and Venturiconversion piece. The combination produces a high induction ratio ofsecondary air to primary air with minimum primary air nozzle pressure atlow noise level.

Having thus described my invention, I claim:

1. An air conditioning unit comprising an elongated primary air wind boxhaving a primary air inlet; said wind box also having a longitudinallyelongated outlet opening in one of its longitudinal walls; a firstsubstantially flat longitudinal wall portion initiating at the outletopening and extending away from the wind box parallel with the majoraxis of the elongated opening; a second longitudinal wall portionlocated adjacent the downstream limit of the first longitudinal wallportion to cooperate therewith in forming a restricted passage forreceiving primary air and secondary air; the space between the secondlongitudinal wall and wind box constituting a secondary air inlet; and aheat exchange member located in the secondary air inlet in substantialparallelism with the first wall portion.

2. The combination of claim 1 wherein the heat exchange member includesa series of finned coils, the edges of the fins closest to the firstlongitudinal wall portion defining a plane diverging slightly from saidfirst longitudinal wall portion in a downstream direction.

3. The combination of claim 1 wherein the heat exchange member includesa series of finned coils, the edges of the fins closest to the firstlongitudinal wall defining a plane diverging from said firstlongitudinal wall portion in a downstream direction at an angle of aboutthree degrees.

4. The combination of claim 1 and further including third and fourthlongitudinal wall portions diverging from the downstream edges ofrespective ones of the first and second wall portions to define aVenturi for handling the primary air-secondary air mixture.

5. The combination of claim 1 and further including third and fourthlongitudinal wall portions diverging from the downstream edges ofrespective ones of the first and second wall portions to define aVenturi; said heat exchange member including a series of finned coils,the edges of the fins closest to the first longitudinal wall portionextending substantially in line with said fourth wall portion.

6. The combination of claim 1 wherein the wind box is provided with alongitudinal partition extending between the primary air inlet andoutlet opening, and longitudinal openings are provided in the partitionfor distributing the air evenly to all points along the outlet opening.

7. The combination of claim 6 wherein the partition includes a firstwall section extending from a point adjacent the outlet opening and asecond wall section extending angularly from the first wall section in adirection away from the outlet opening; and the partition openings areformed in the second wall section.

8. The combination of claim 1 wherein one wall of the wind box is atleast partially defined by a planar extension of said first longitudinalwall portion, and one edge of said outlet opening is formed by saidplanar extension.

9. The combination o f'claim 1 wherein one exterior face of the wind'boxis trough-shaped to receive condensate from the heat exchange member;the heat exchange member includes a series of fins having their upstreamedges extending upwardly from the wind box toward a point overlying thetrough-shaped face; and a drain trough is provided at the upstream endof the second longitudinal wall portion; whereby condensate is collectedwhether the unit is positioned with the upstream edges of the finslocated in a generally horizontal plane or in a generally verticalplane.

References Cited in the file of this patent UNITED STATES PATENTS1,995,667 Cano Mar. 26, 1935 FOREIGN PATENTS 379,430 Great Britain Sept.1, 1932 884,634 France Aug. 23, 1943 704,447 Great Britain Feb. 24, 1954

